Feeding mechanism for rock drills



0 sept. 22;;1936.- J gums y 2,055,003

FEEDING `MECHANSlVl FOR ROCK DRILLS l ATTORNEY Sept. 22', 1936.

J. c. CUR-nsr` FEEDING MEGHANISM FOR ROCK DRILLS Filed June 8, 1936 2 Sheets-Sheet 2 INVENTOR ATTORNEY Patented Sept. 22, 1936 UNITED STATES PATENT OFFICE FEEDING MECHANISM Fon ROCK DRILLS Application June 8. 1936, Serial No. 84,121

7 Claims.

This invention relates broadly to rock drills, but more particularly to a feeding mechanism for rock drills of the percussive type.

One object of this invention is to produce a rock drill feeding mechanism designed and constructed whereby feeding motion may be impartedto the drill either automatically due to the vibratory movement of the drill or manually due to the rotationof a hand operated element such as a hand crank or thev like.v v

Another object of this invention is to provide a feeding mechanism for rock drills with means readily operable for selectively transforming the feeding mechanism in a manually or automatically operated mechanism.`

Other objects and advantages more or less ancillary to the foregoing and the manner in which the various objects are attained, reside in thespeciic construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification, in the claims of which there are assembled certain specific combinations of parts and specific constructions indicative of the scope and spirit of the invention.

In the drawings:

Fig. 1 is a longitudinal view partly in section of a rock drill having theinvention applied there- Fig. 2 is an enlarged longitudinal sectional view illustrating parts of they feeding mechanism in one position.

Fig. 3. is a view similar to Fig. V2 illustrating some of the parts ina different position.

Figs. 4, 5, and 6 are cross sectional views taken ina planev indicated by lin-e 4 4 in Fig. 2' and illustrating parts of the mechanism in different position.-

Fig. '7 isa cross sectional View indicated by line 'I--T in Fig. 2'.

taken in a plane Fig. 8 is a longitudinal sectional View taken in a plane indicated by line 8'8 in Fig; 2.

Fig. 9 is an enlarged perspective view of one' of the pawls used in the feeding mechanism.

Referring to the drawings in which like symbols designate corresponding parts throughout the several' views, I5 represents a drilling motor having a piston (not shown) reciprocable therein for imparting blows to a drill steel I6 which is adequately mounted within the front end of the rock drill.

` Below the drill, there is the usual stationary support I'I on which the drill is slidably guided for longitudinal movementrthereon in rboth directions. This support includes a shell having (Cl. Z55-45) guideways in its upper Wall adapted to slidably receive the drill. Each side of the shell is provided with apertured lugs IB having a tie rod I9 extending therethrough beyond the left end of the shell. Through these tie rods is secured to the right end of the shell the usual cross head 20 forming a front bearing for a feed screw 2l disposed longitudinally of the shell. The other end of the screw is operatively mounted within a stationary housing 22 which is carried by the end portions of the rods I9 extending beyond the left end of the shell. Depending from the drilling l motor I5, there is the usual apertured lugs 23 having adequately mounted therein a stationary nut 24 in threaded engagement with the screw 2 I.

Referring now more particularly to the present invention, that is the mechanism contained within the stationary housing 22, it will be seen that th-e screw 2| has a smooth portion 25 extending into the housing 22 and forming with the normal diameter of the screw an annular shoulder 26 abutting a washer 21. Locked on this smooth portion of the screw 2I by a key 28, there is a disk 29 having one side wall in abutting engagement with an internal vertical wall 30 of the housing 22. This disk has its peripheral wall provided with ratchet teeth 3| with which a plurality of pawls 32 and 33 are capable of engagement. These pawls are pivotally mounted within the wall of the housingv 22. Each pawl has a torsional spring 34 wound around one end 35 thereof for constantly urging the pawl in engagement with the teeth 3|. In the present construction, there is shown six pawls, four pawl's 32 being located for alternative engagement with one side of the teeth 3|, and two pawls 33 for alternative engagement with the other side of the teeth 3|. Each pawl has its wing formed with a relatively narrow land 36 capable of engagement with the peripheral wall 31 of a rotatable disk 38 as will be explained later.

Also locked on the smooth portion of the feed screw 2| by the key 28, there is a gear 39 having a sleeve portion 40 abutting against the toothed member 29. The axial movement of the screw is limited in one direction by the shoulder 26 engaging the washer 21, and in the other direction by a nut 4I engaging the gear 39. On the sleeve portion 40 of the gear 39 is rotatably mounted the disk 38. This disk has an. integral stem 42 extending from its peripheral wall 31 to the exterior of the casing 22 through a radially disposed opening 43. On the stem is mounted for movement therewith an arcuated spring cover 44 having detents 60 engageablewithin notches 6I for holding the handle 45 and disk 38 in selected positions. The end of the stem 42 is threaded to receive a handle 45 by which the disk 38 may be rotated. The peripheral wall portion of the disk 38 with which the land 36 of the pawls 32 and 33 is capable of engagement is provided with two diametrically opposed cut away portions or notches 46 of a length su'icient to accommodate at least two pawls.

Capable of engagement with the gear 39, there is a slidable pinion 41 having a front and rear shank 48 and 49, the latter extending to the exterior of the housing to receive a handle 50 secured thereon by a key 5| and nut 52. Interposed between the inner wall of the housing and the pinion 41, there is a compression spring 53 constantly urging the end of the front shank 48 in engagement with the adjacent side wall of the disk 38, which side wall is provided with-a V- shaped cam 54.

Operatively mounted within the end wall of the housing 22, there is a' screw 55 having its inner end engaging a cap 56, which is held against rotation by a dowel pin 51. The cap covers the nut 4| and engages the adjacent side wall of the gear 39. To the other end portion of this screw is affixed a handle 58 which may be clamped thereon against relative rotation by a cross bolt 58,l

thus permitting the screw 55 to first engage the cap 56 before the handle is clamped on the screw in the desired position. The handle 58 also carries a spring pressed plunger 62 engageable within detents formed on the external wall of the housing for holding the handle 58 in the desired position.

In the operation of the mechanism, let us assume that the disk 38 is positioned as shown in Fig. 4, with the handle 45.in a vertical position halfway between the ends of the opening 43. In this instance, all pawls 32 and 33 have their respective land 36 engaging the peripheral wall 31 of the disk 36, thus preventing the engagement of the pawls with the teeth 3| of the member 29 and thereby permitting a free rotation of the screw 2| in either direction. In this position of the disk 38, the front shank 48 of the pinion 41 is engaging the bottom of the cam 54 as shown in Fig. 8, thus causing the pinion 41, due to the effort of the compression spring 53, to assume the position shown in Fig. 2, that is in engagement with the gear 39. Since the pinion 41 is in mesh with the gear 39, it will be understood that the mechanism may manually be operated by simply rotating the handle 58, which rotation is transmitted to the feed screw 2| for imparting forward or backward feeding motion to the motor l5 dueto the operative engagement of the nut 24 with the screw 2|.

When it is desired to automatically impart feeding motion to the drilling motor -in a forward direction, the handle 45 and disk 38 may be moved in the position shown in Fig. 5. In this instance, the notches 46 formed on the peripheral wall ofthe disk 38 are positioned to receive the pawls 32 and preventing thereby their respective land 36 to engage the peripheral wall of the disk, thus allowing the engagement of the pawls with the teeth of the disk 26. in a manner calculated to cause their alternative engagement with one side of the teeth 3 I for preventing the rotation of the feed screw 2| in a clockwise direction in Fig. 5. The threads of the feed screw 2| are preferably of a fast pitch corresponding of course to those of the feed nut 24, and thereby causing rotation of the screw upon longitudinal movement of the motor l5 on the The pawls 32 are locatedV support. During the operation of the motor I5, the piston reciprocable therein will impart jars to the motor tending to move the latter back and forth relative to the support, and thereby tending to effect an oscillatory motion of the feed screw 2|. However due to the engagement of the pawls 32 with the teeth 3|, the screw is locked against rotation in a clockwise direction, thus preventing the rearward longitudinal movement of the motor and automatically effecting a step by step forward feeding movement of the latter.

When it is desired to automatically feed the motor rearwardly, the handle 45 and disk 38 may be positioned as shown in Fig. 6. In this instance the notches 46 are positioned to accommodate the pawls 33, permitting thereby their engagement with the other side of the teeth 3|. Simultaneously the pawls 32 are again lifted out of engagement with the teeth 3| due to their respective land 36 engaging the peripheral wall of the disk 38. With the pawls 33 engaging the teeth 3|, the feed screw is locked against rotation in a counterclockwise direction in Fig. 6, thus causing the jars imparted to the motor I5 to automatically effect a step by step rearward motion of the motor.

During the movement of the handle 45 and disk 38 from the position shown in Fig. 4 to either position shown in Figs. 5 and 6, the front shank 48 of the pinion 41 will ride the cam 54, thus forcing the pinion out of engagement with the gear 39 against the effort of the compression spring 53. When the disk 38 is located as shown in Figs. 5 and 6, the front shank 48 engages the top of the now stationary cam 54 to maintain the pinion 41 out of engagement with the gear 39. In this manner the crank handle is automatically shifted and maintained out of operative engagement when the mechanism is being transformed for automatic feeding. When the handle is positioned as shown in Fig. 4, the front shank 48 again riding the cam 54 downwardly will allow the pinion 41 to be shifted by the spring 53 into engagement with the gear 39, thus not only moving the pawls 32 and 33 out of engagement with the teeth 3|, but automatically transforming the mechanism for manual operation.

The screw 55 and handle 58 constitute a brake mechanism capable of regulating the freedom with which the feed screw 2| is adapted to rotate. Through the handle 58, the screw 55 may be rotated to exert pressure on the cap 56 for effecting a more or less complete clamping action of the gear 39 and member 29 between the cap 56 and the vertical end wall 30, affecting thereby the free rotation of the feed screw 2| for regulating the feeding speed of the motor. This brake mechanism is especially desirable when collaring a hole, in which instance, the brake is set to lock the screw against rotation, preventing thereby the movement of the motor relative to the support.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or confining and it is to be further understood that various rearrangements of parts and modification of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

l. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having jars imparted thereto, of a stationary nut carried by the motor in threaded engagement with a rotatable screw carried by the support, the rotation of said screw effecting the feeding motion of the motor, a duality of mechanism connectable with said screw one for manually rotating the screw and the other for automatically rotating itV due to the jars of the motor, and V,unitary means for selectively connecting either of said mechanisms with said screw.

2. In a drilling apparatus, the combination `with a support of a drilling motor slidable on the support having jars imparted thereto, of a feeding device for the motor including a pair o f elements in threaded engagement with each other, one of said elements being rotatable relative to the other for imparting feeding motion to the motor, a duality of mechanisms connectable with said rotatable element one for manually rotating the same and the other for automatically rotating it due to the jars of the motor, and unitary means for selectively connecting either of said mechanisms with said rotatable element.

3. In a drilling apparatus, the combination With a support, of a drilling motor slidable on the support having jars imparted thereto, of a feeding mechanism including a pair cf elements in threaded engagement with Veach other, one of said elements being rotatable relative to the other for imparting feeding motion to the motor, stop means connectable With said rotatable element for effecting the rotation thereof in one direction due to the jars of the motor, manually operable means connectable with said rotatable element for effecting the rotation thereof independently of said stop means, and a single member operable for selectively connecting either of said means With said rotatable element.

4. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having jars imparted thereto, of a rotatable screw in threaded engagement with the motor for imparting feeding motion thereto, manually operating means for said screw, automatically operating means capable of effecting the rotation of the screw due to the jars of the motor, and unitary means for selectively connecting either of said operating means with said screw.

5. In ar drilling apparatus, the combination With a support, of a drilling motor slidable on the support having jars imparted thereto, of a rotatable screw in threaded engagement with the motor for imparting feeding motion thereto, manually operating means for said screw, automatically operating means capable of effecting the rotation of the screw in either direction due to the jars of the motor, and unitary means for selectively connecting either of said operating means with said screw and controlling the direction of rotation of the latter when Connected With said automatically operating means.

6. In a drilling apparatus, the combination with a support, of a motor on the support having jars imparted thereto tending to move the motor back and forth with respect to the support, a. screw in threaded engagement with the motor normally rotated due to the movement of the latter onthe support, stop means for pre venting the rotation of the screw in one direction to enable a step by step movement of the motor in a corresponding direction, manually operable means connectable with the screw for rotating the same in either direction, and unitary means for rendering said stop means ineffective and for connecting said manually operable means with said screw.

'7. In a drilling apparatus, the combination with a support, of a drilling motor on the support having jars imparted thereto, a screw in threaded engagement with the motor normally oscillated due to the jars of the motor, a mover ment transmitting mechanism connectable with said screw for rotating the same to effect continuous slidable movement of the motor, a movement arresting mechanism connectable With said screw for controlling the direction of rotation thereof resulting from the jars of the motor, and unitary means for selectively connecting either of said mechanisms with said screw.

JOHN C. CURTIS.

DI S O L. Al M E R 2,055,003'.-John C. Curtis, Garfield Heights, Ohio. FEEDIN'G MECHANISM FOR ROCK DRILLS. Patent dated September 22, 1936. Disclaimer led September 29, 1937, by the assignee, The Cleveland Rock Drill Company. Hereby enters this disclaimer t0 claims 1, 2, 4, and 5 of said specification.

(Oljcvlal Gazette Octobw` 19, 1937.) 

